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[ctsim.git] / doc / ctsim-gui.tex

diff --git a/doc/ctsim-gui.tex b/doc/ctsim-gui.tex
index 94d02ec1c6076ffc0317771094b42cbdb862c015..c33cffd8f10188e36b52ecfb6e7be1c68ef4e0fd 100644 (file)
--- a/doc/ctsim-gui.tex
+++ b/doc/ctsim-gui.tex
@@ -408,20 +408,13 @@ filter and can range from \texttt{0} to \texttt{1}.
 At a setting of \texttt{1}, the Hamming filter is the same as the bandlimit filter.
 At a setting of \texttt{0.54}, the Hamming filter is the same as the Hanning
 window.}
-\end{twocollist}
-
-\begin{twocollist}
 \twocolitem{\textbf{Filter Method}}{Selects the filtering method.
-For large numbers of detectors, \texttt{rfftw} is optimal. For
-smaller numbers of detectors, \texttt{convolution} can be
-faster.
-\begin{itemize}\itemsep=0pt
-\item \texttt{convolution}
-\item \texttt{fourier} - Uses simple Fourier transform.
-\item \texttt{fourier-table} - Optimizes Fourier transform by precalculating trigometric functions.
-\item \texttt{fftw} - Uses complex-valued Fourier transform with the \emph{fftw} library.
-\item \texttt{rfftw} - Uses optimized real/half-complex Fourier transform.
-\end{itemize}
+For large numbers of detectors, the FFT-based filters are preferred whereas for
+smaller numbers of detectors \texttt{convolution} can be
+faster. When \emph{Advanced Options} have been turned off, this menu only shows
+the two basic choices: \texttt{convolution} and \texttt{FFT}. However, when
+\emph{Advanced Options} have been turned on, additional selections are available as
+discussed in the next section.
 }
 \twocolitem{\textbf{Interpolation}}{Interpolation technique.
 \texttt{cubic} is optimal when the
@@ -445,6 +438,17 @@ default to optimal settings and don't need to be adjusted except
 by expert users.
 
 \begin{twocollist}
+\twocolitem{\textbf{Filter Method}}{Selects the filtering method.
+The general comments about this parameter given the previous section still apply.
+With \emph{Advanced Options} on, the full set of filter methods are available:
+\begin{itemize}\itemsep=0pt
+\item \texttt{convolution}
+\item \texttt{fourier} - Uses simple Fourier transform.
+\item \texttt{fourier-table} - Optimizes Fourier transform by precalculating trigometric functions.
+\item \texttt{fftw} - Uses complex-valued Fourier transform with the \emph{fftw} library.
+\item \texttt{rfftw} - Uses optimized real/half-complex Fourier transform.
+\end{itemize}
+}
 \twocolitem{\textbf{Backprojection}}{Selects the backprojection
 technique. A setting of \texttt{idiff} is optimal.
 \begin{itemize}\itemsep=0pt